ABYC disconnect for propulsion battery

https://www.socomec.us/wp-content/u..._INSTRUCTION-MANUAL_2018-12_542122-F_EN-I.pdf
these look pretty good
I haven't seen any of these required disconnects on any boats or on any electric inboard manufacturers website.

 

Are these for those 78kw batteries? Or do you get to split them down?

I apologize, but my curiosity is killing me.

168v @ 300 amps is 50,400 or 50kw, so I am also wondering about my math error v 78kw, not to mention all these guys would be sort of amazed at the power plant

You have much better support than my simple curiousity can provide. But hopefully, I am not too annoying.

 

As I understand it David's case is DC of more than 50 V or AC of more than 300 V and therefore covered by the ABYC TE-30 (outside the scope of ABYC E-11).

I'm building also an electric driven boat but only under 50 V DC (24 V system). While the safety requirements in this case are lesser I will do more as is mandatory. For some time I was looking for a main breaker (battery disconnect switch) and it is really difficult to find an appropriate device (relatively low voltage combined with relatively high amperage, not too pricey, not too bulky, not too heavy).

Today I ordered one of this (different to the pic amperage is 125 A, to be wired as shown in the 2nd pic):


(It's a brandless cheap (30 EUR) Chinese product and I will try it.)

And in addition 4 of this (24 V, 275 A, to currentless disconnect each of the batteries from the bank if necessary):



(Sorry for the thread drift - but it may be of interest for anybody.)

 

How would one go about testing very high load HV switches/ breakers/ disconnects (before they are installed?) to verify the required ratings are as they should be? Sometimes they cut corners on the Chinese stuff, has been my experience..

 

I'd start here...DC Voltage Interface Standards for Naval Applications. Which a quick inspection leads to IEEE std 1709... Recommended Practice for 1 kV to 35 kV Medium-Voltage DC Power Systems on Ships... (yeah, I know, but 30 years of habits.)

https://apps.dtic.mil/sti/pdfs/AD1015078.pdf

1709-2018 - IEEE Recommended Practice for 1 kV to 35 kV Medium-Voltage DC Power Systems on Ships https://ieeexplore.ieee.org/document/8569023

 

@Heimfried thanks for posting.

That breaker switch might be good for my next project.

Let us know how it works out.

 

Testing:
Without special equipment it will be hard to perform real tests of the device. So I will do the simple things: checking with a multimeter if the manual on/off switching works on all 4 poles, do the same under load with current at or near I nominal (125 A). Provoke a short cut at each pole (one pole at a time) and control if are all poles are disconnected. The short cut triggers the breaker in a magnetic way, the overload triggers bimetallic and relative slowly. So I will look, if I will be able to apply an overload current for a while without depleting my batteries.
This tests (and some combinations of them) - if outcome is positive - should give me some confidence.

@fallguy
As it is sitting at the bottom of the page, did you notice my answer (#15) to your question?

 

@Heimfried

David has been a resource and a friend; so I don't fancy messing up his thread too much beyond asking some questions or saying something silly enough to bring smarter men to speak. I saw your response and tried to decipher whether the switch he sourced was right, but I gave up and could not find the relevant content. Thread drift is fine if we get back to the OP. My only intent was to understand in specifics why his sourced switch was not correct. I was not able to understand, but this is all for him, so if he needs more assistance; he can reply.

Thanks for the contributions.